Machinery for forming bales of crop stock, e.g., of clover or alfalfa hay, are long known in the art. In a representative operation, the crop stock would be mowed and then gathered into a windrow. A baler, either self-propelled or pulled by some other machine such as a farm tractor, would then be driven down the windrow from which it would gather the crop stock, form a bale in a bale-forming chamber, and then discharge the bale from the baler. Typically such machines form bales having either a cylindrical configuration or a rectangular configuration.
Balers for forming cylindrical bales were at one time designed and constructed to form bales capable of being easily handled manually by an adult. Such bales would typically be approximately two feet long, have a maximum diameter of about three feet, and weigh at most 100 lbs. With the reduction of available farm labor, as well as its increasing costs, however, in the last two decades there has been a move to produce cylindrical bales of a larger size to make a baling operation less labor intensive. These bales typically have a length of about five feet, a maximum diameter of about five feet, and weigh approximately 1,500 lbs. Obviously a single farmer with the appropriate mechanical bale-handling apparatus is capable of handling a large quantity of crop when in such a form.
Each bale shape had its advocates and its particular advantages and disadvantages. One of the disadvantages that round balers suffer in comparison to square balers is that a square baler is capable of a continuous baling operation. That is, unlike the round baler, a square baler is able to continue baling while discharging a tied-up bale of crop stock. With a round baler it is necessary to discontinue pick up of the crop from the windrow while the baler finishes forming the bale, ties the bale with wire or twine, and discharges the bale from the rear of the baler to the ground. Additionally, it is usually necessary to back the round baler up prior to discharging the bale so that no crop stock would be passed over by the baler. These extra movements increase baling time or if not performed resulted in un-baled crop stock being left in the field. These problems were further exacerbated with the movement to the larger balers
The large round balers typically include front and rear portions forming a bale formation chamber therebetween. These portions are often pivotally attached at the tops thereof such that the rear portion or gate may be moved apart from the front portion for discharging of a bale in a manner similar to the opening of a clam shell. Because it is necessary that the rear portion of the baler be closed before baling recommences, when discharging a bale with the present large apparatus it is necessary to stop the forward movement of the baler, reverse directions, back up a predetermined distance, discharge the bale, move forward, close the rear portion, and then begin baling again. Failure to perform such a maneuver would result in the necessity of discharging a bale and then pulling ahead a sufficient distance to close the rear portion of the baler, resulting in unbaled crop stock being left on the ground. A further disadvantage of such balers is that on occasion the rear portion of the baler can strike a discharged bale when closing and can suffer damage thereto.
Prior art attempts addressing these problems have taken several approaches, namely, the ramp, the conveyor, the pusher, and the kicker. Typical of the ramp approach are U.S. Pat. No. 3,974,632 to VanderLely, U.S. Pat. No. 4,559,770 to Mast, and U.S. Pat. No. 4,566,380 to Clostermeyer et al. The VanderLely patent discloses a ramp that extends rearwardly and groundwardly of the baler for bale discharge. The ramp is formed by a lower portion of the rear wall of the baler. The Mast patent discloses a ramp that is pivotally connected to the baler frame so that the bales may be rolled to the ground upon bale discharge. Similarly, Clostermeyer teaches a ramp attached to the rear of the baler and down which a bale rolls upon discharge.
U.S. Pat. No. 4,683,815 to Van Ryswyk teaches the attachment of a chain-driven conveyor system to the rear of the baler. Upon discharge of a bale from the rear of the baler the conveying system moves the bale rearwardly of the baler to a discharge position on the ground. The conveyor system is pivotally mounted to the baler and projects rearwardly therefrom. Upon opening of the rear portion of the baler, the conveyor pivots downwardly in response to the weight of the bale such that its rearwardmost position contacts the ground.
Representative of the pusher-type solution are U.S. Pat. Nos. 4,779,527 to Ardueser et al, and 4,483,247 to Coeffic. These patents teach the use of a U-shaped pusher mechanism pivotally attached to the front section of the baler that is used to push a discharged bale away from the baler after discharge and to retain the bale in such a position while the rear gate of the baler closes.
Representative bale kickers are found in U.S. Pat. Nos. 4,458,587 to Jennings, 4,406,221 to Parrish et al, and 4,206,587 to Freimuth et al. Each of the three referenced patents teaches a bale kicker comprised of a U-shaped structure attached to the rear portion of the baler. The U-shaped structure is spring loaded such that as a discharged bale rolls over the crossbar portion of the "U," the coil spring is stretched thereby allowing the U-shaped kicker to pivot towards the ground. As the center of gravity of the bale passes over the bar rearwardly of the baler, the spring begins to retract, pivoting the U-shaped member upwardly and providing additional impetus to the bale as it is discharged from the baler. This additional rearward impetus is referred to as a kick and results in the bale being discharged slightly further rearwardly from the baler than it otherwise would.
Each of the prior art attempts just described fail to completely solve the problems of bale discharge. For example, while basically a simple device, the kicker mechanisms require springs of great strength in order to provide a rolling impetus to a bale which may weigh as much as 1,500 lbs., and thus they may fail to move the bale far enough away from the baler. In addition, as the kicker returns to its position, it does so with a force directly proportional to the spring constant of the springs used. This can result in loud clanging noises as the kicker returns to its position as well as in jarring motions and structural damage to the baler. The ramps also provide a simple solution, however they can fail to produce the desired results when baling is carried on in terrain that is not flat. The more complicated solutions of the conveyor and the pusher present additional mechanical breakdown problems. For example, the conveyor system described relies upon a chain-driven conveyance system to move a bale away from the gate. The pusher of the referenced patent utilizes a shock absorbing system to work against the energy of the spring assembly utilized in the mechanism taught there.
Thus there is a need for a bale discharge apparatus which performs several desirable functions. First, such an apparatus should ultimately deposit a bale on the ground at a desired position rearward of where it would be if it simply fell from the rear of the baler. Second, it should retain the discharged bale at the desired discharge position while the rear portion of the baler closes, thereby preventing the rear portion of the baler from coming in contact with a discharged bale. Third, such an apparatus should retain a discharged bale at the desired position so that the operator can stop the baler, discharge a bale therefrom, and then continue onward with no back up maneuvering necessary, and therefore no unbaled crop left in the field. Fourth, such an apparatus should be mechanically simple and impart minimal reaction forces to the baler from the bale discharge.